1. Field of the Invention
The invention relates to a method of producing a wheel bearing apparatus.
2. Description of Related Art
FIG. 8 illustrates a wheel bearing apparatus 500 described in Japanese Patent Application Publication No. 2013-217419 (JP 2013-217419 A). The wheel bearing apparatus 500 includes a hub spindle 520, and an outer ring 510 disposed radially outward of the hub spindle 520. The hub spindle 520 has a flange 522. The flange 522 is formed at an outboard-side end portion of the hub spindle 520 in the vehicle-width direction. A wheel (not illustrated) is attached to the flange 522. The outer ring 510 is fixed to a vehicle fixed member. The hub spindle 520 is supported such that rolling elements 530 allow the hub spindle 520 to rotate relative to the outer ring 510.
In the wheel bearing apparatus 500, entry of foreign matter (e.g. rain water or muddy water splashed from a road surface) into a space between the hub spindle 520 and the outer ring 510 is desired to be prevented. In view of this, the space between the hub spindle 520 and the outer ring 510 is sealed at both ends. On the outboard side of the space in the vehicle-width direction, a sealing device 540 is disposed between a root portion of the flange 522 of the hub spindle 520 and the outer ring 510, and the sealing device 540 is assembled to the root portion of the flange 522 of the hub spindle 520 and the outer ring 510, as illustrated in FIG. 8. The sealing device 540 includes a sealing member 560, and a slinger 550 disposed adjacent to the sealing member 560. The sealing member 560 includes a core 570 and a seal body 580. The core 570 has a tubular portion 570a press-fitted to the inner peripheral surface of the outer ring 510, and an annular portion 570b projecting radially inward from the tubular portion 570a. The seal body 580 is attached integrally to the annular portion 570b. The seal body 580 is formed of an elastic body.
The slinger 550 has a slinger tubular portion 550a press-fitted to the hub spindle 520, and a slinger annular portion 550b projecting radially outward from the slinger tubular portion 550a. A seal lip 580a that is a distal end of the seal body 580 is slidably in contact with the slinger annular portion 550b. With the contact between the seal lip 580a and the slinger annular portion 550b, the space between the hub spindle 520 and the outer ring 510 is sealed off from a space on the outboard side in the vehicle-width direction. The slinger 550 is made of stainless steel, and thus does not readily rust. Thus, the seal lip 580a in contact with the slinger annular portion 550b is prevented from coming into contact with rust. As a result, abrasion of the seal lip 580a, which would occur due to contact with rust, is prevented.
For example, the seal lip 580a may be brought into contact with the flange 522 to seal off the space between the hub spindle 520 and the outer ring 510. In this case, when the flange 522 gets rusty due to the water thrown up by the wheel (not illustrated), the seal lip 580a comes into contact with the rust, leading to abrasion of the seal lip 580a. However, in the technique described in JP 2013-217419 A, provision of the slinger 550 prevents abrasion of the seal lip 580a, which would occur due to contact with rust, thereby preventing a decrease in the sealing performance.
In the technique described in JP 2013-217419 A (see FIG. 8), if the distance between the seal body 580 and the slinger 550 is excessively short, the contact pressure applied from the seal lip 580a to the slinger annular portion 550b becomes excessively high, and thus the torque applied to the wheel bearing apparatus 500 becomes excessively high. On the other hand, when the distance between the seal body 580 and the slinger 550 is excessively long, the contact pressure applied from the seal lip 580a to the slinger annular portion 550b becomes excessively low, and thus desired sealing performance cannot be achieved. It is to be noted that, JP 2013-217419 A does not describe any method of performing the positioning of the slinger 550. Therefore, the inventor has found room for improvement in the positioning accuracy of a slinger in this type of wheel bearing apparatus.